chore: release 0.2.7

chore: cut release branch and prepare 0.2.6

chore: release 0.2.5

release: 0.2.4

release: 0.2.3

chore: release 0.2.2

release: 0.2.1

release: 0.2.0

New:
- requantize helper by @calmitchell617,
- StableDiffusion example by @thliang01,
- improved linear backward path,
- AWQ int4 kernels.

release: 0.1.0

- group-wise quantization,
- safe serialization.

release: 0.0.13

- new `QConv2d` quantized module,
- official support for `float8` weights.

- fix `QbitsTensor.to()` that was not moving the inner tensors,
- prevent shallow `QTensor` copies when loading weights that do not move
  inner tensors.